Question

the process that inolves the moving of one substance against its concentration gradient by using energy from a second substance moving down its concentration gradient is known as?

Answer 1

The process of moving of substances against concentration gradient means from lower to higher concentration region requires energy. The energy is used in the form of ATP. The active transport process may also occur against the electro-chemical gradient. The electro-chemical gradient is generated by charge difference between ions across the membrane that creates difference in membrane potential. The ion transport across membrane may generate electro-chemical gradient and membrane potential difference across the membrane. The movement of substances against concentration or electro-chemical gradient is known as active transport and this occurs with help of cellular energy ATP. Another mechanism called secondary active transport or co-transport occurs by using ATP to move the substance against the concentration gradient. The ATP is generated by other substance moving down the concentration gradient. Therefore, the secondary active transport is the mechanism carried out by the free energy of the electrochemical gradient generated by another mechanism such as ion pumping ATPase used to transport a molecule against its concentration gradient. For example the Lactose transport into a cell by Lactose Permease is carried out by simultaneous co transport of H⁺ ions. In this case the ion gradient is maintained by the oxidative metabolism.